FTP or Anaerobic Training?

A client of mine asked if his limiter in category 1/2/3 races was truly his FTP. He felt that the surges in the 1/2/3 races were much harder than in the 3/4 field. He was also wondering even if his FTP was his limiter was it actionable to focus on it this late in the racing season? I do believe his FTP was his limiting factor and that it is never too late in the season to train it. Here is my evidence I sent him.